In the production of a large volume of pressure sensitive labels, it is common to feed a web of pressure sensitive adhesive label material releasably attached to a paper backing or carrier web from a supply roll into a printing press or station where the labels are printed. The combined webs are then fed through a rotary die cutter which die-cuts the labels on the paper carrier web and also forms a skeleton or lattice from the web of label material. The lattice is then peeled away from the carrier web as scrap and wound into a roll of scrap lattice material. When the wound roll of lattice material arrives at a certain diameter and weight, the label production machine or system is stopped in order to remove the wound roll of lattice material and to start a new roll. This operation involves downtime of the label production machine and also requires additional labor to lift and remove the scrap roll of lattice material from the label production machine and to transport the roll on a pallet to a scrap storage area or a large waste receptacle. It is also known to direct the scrap skeleton web or lattice into a suction hood and duct work which conveys the lattice with exposed adhesive a short distance to a trash receptacle located close to the label production machine. However, the exposed adhesive on the lattice web sometimes causes the lattice web to stick or drag on the conveyor duct, and frequently, there is no space to locate a large scrap receptacle close to the label production machine.
The present invention is directed to an improved system or apparatus for continuously removing and conveying a scrap lattice of adhesive label material and which provides for conveying the scrap lattice over a long distance through an air suction conveyor duct. Thus the lattice may be continuously conveyed to a remotely located large scrap container, thereby eliminating the above described downtime of the label production machine and the labor involved in handling and transporting scrap lattice rolls. In accordance with one embodiment of the invention, a web of scrap skeleton or lattice with exposed adhesive on one side is directed into a curling device or cone which curls, folds and rolls the lattice web into a condensed and concentrated rope-like body with the adhesive on the strips facing inwardly.
The rope-like body of scrap lattice material is sucked into the center portion of a pneumatic conveyor duct by air flowing through an annular inlet surrounding the body as it exits the curling device. Thus the body of scrap lattice material is entrained in the center of the duct where the air velocity is greatest, thereby minimizing the chance of any exposed adhesive on the outer surface of the body attaching or dragging on the inner surface of the conveyor duct. The inner surface of the curling cone is flame sprayed with a metallic compound to produce a rough and abrasive interior surface, and this surface is coated with a silicone polymer to provide a slick and non-sticky rough inner surface so that the adhesive on the lattice web will not adhere to the curling cone.